Elevator safety appliance



April 20, 192e. 1,581,458

D. 1.. LINDQUls-r ELEVATOR SAFETY APPLIANCE Filed July 11, 1924 2 sheets-sheet '2v f is actuated.

Patented. Apr. 2o, v19261.

"UNITE-D' "STA/T ES PATi31\JT OFFICE;v

DAVIDL. .Lnntiursn orA HARtrsDALEfNEw Yonai,A Assiduo?.Y 'ro o'rrs ELEVAT,0R

COMPANY', or J'EnsEY'crTYgNEW JERSEY,l A CORPORATION' orf New JERSEY.

'ELVATOR SAFETY APPL'IANcn- Application filed July 11, 1924. serieu No. rasees,

, is a speciiication.

i' This inyention relates to "safety `devices 10 for the parts of an elevatorsystem traveling iii the hatchway, and particularly to safety 'l 'brakes adapted to .be applied to a stationary rail for bringing the moving parts to a stop' Vin the event? of their traveling above a pre- 1 15 determined speed.4

One object of the inventionl is to apply a` substantially constant retarding force'in predetermined amount tobring'the moving parts to a stop whenever the-'safety device `Another Objectis tp provide such` a safety brake which, after it. has been applied to' stop the moving parts, will be released upon their being moved in the reversedirection,l

A f-urt 1er object is to provide, in anele fcation and claims,

In a preferred embodiment ofthe inv-ene,

tionthe safety 1brake,which is mounted on the elevator' carjliasa pair of rollers disposed-on oppositesides-of the guide rail and. arranged to -be brought into rolling contact with theguide rail when the safety brake is applied. p 40 between each roller andthe rail to exert a pressure between-them and at the same time lresist rotation the roller aboutits axis...

The amount of such pressure is automati lcally regulated by; an vadjustable resilient vator system equipped with buffers at the end of travel of the movingpartsymeans' Other objects willappear from the speci-- A yielding member is employed force acting substantially .parallel to the rail, and this resilient force determines the to, stop l'the elevator car at the limit of i-ts" vdownward amovenient, occasion may arise' when the safety'brake 1will be acting to stop the I'car at the time that it strikes the buffer.

In such event the retardationof the car will be too rapid due to the :action of both the buil'er and safety brake, so that -passengers may be injured and theequipm'ent damaged; To avoid this thethickness `of Vthe' railis decreased atdpoints in the-hatchY .whereboth the butler an Aact simultaneously. so ,that the safety brake safety brake mightn cannot be applied lthese points-tostop the car; -An embodiment A,of the invention wherein a-y safety brake is' carried .by 'thefcar and buffers are mountedin the elevator pitis described in connection with' the l accompanying drawings, }n..wh1ch,'-f t ew of an' ele;

Figure .1- s a schematic Ivi Ivator system t-o which safety device'sgin accordance with this invention areappl'ied,

Figure 2 is a' front elevation on-'a'larger scale of a portionof the lfrail used inthe elevator` system shown in Figure 1,

Figure 3 is an 'end elevation of the-safety' brake `in. released position, with icertain.

lparts removed, and .shows thev operating mechanismitherefor, I

, Figure 4 is an elevation of the safety brake in applied position,

` Figure 5 is a detail' view of one of t-he engaging rollers offthe safety brake,.and

y Figure 6 isasectional view taken on line 6-6 of Figure 3.

Referring to Figurel 1, `the e'levator,..sys;

`tem includes the car l0 which is suspended" l by cables 11 extending over a driving drum 12 to counterweight 13.' The drum 12is driven by a' motor .14 'and has an electro magnetic brake 15. Stationary guide, rails 16 are provided in the hatchwayand the car 10 vhas an upper set ofgguide shoes 17 and a lower Set of guide shoesv 18.

low the point 19, Figure 1, inthe manner The thickness of the guide rails is decreased be@ shown in Figure 2 for a purpose'to be hereinafter pointed out.

Buffers '21, Iindicated as oil Vbufl'ers in'Figiire 1, are provided in the elevator pit for bringing thejcar to a stop in the`event that the car passes ltoo farbelow the lower landing 20.

' The safety brakes 24 are mounted one on 'each end of the'safety plank ,22 which is secured to the bottomv of the car.` -Safet plank 22 supports a pair of shafts 23= whic operate upon safety brakes 2,4 to cause them to engage the guide rails; i

As 'best shown in Figure 3 shafts 23 are connected by'a. pair of vgears 25 so as to has a lever arm 31 to which lis berotated together and a bevel ydriving gear 26 secured'to a shaft 27 meshes with a cor- I responding bevel gear formed on the back from the `bottom of car 10 adjacent'tofone side thereof, and from there rope 32 extends upwardly' to hitch 34 on governorrope 35. Hitch -34'isnormally held ina releasing carrier 51 attached to the car'.- Governor rope 35 extends from hitch l34 over a sheave 36 of a centrifugal governor and thence around tensioning sheave38 which has a weight 39 jmount'ed in guides 40.

Upon excessive speed of thefcar, a set of jaws 41 vand 42 are tripped so as to'engage the governor rope. Jaws 41 and 42fhave a gear connection between them so -that they will operate together. Jaw 41 is pivotedat 43, and is provided with an arm 44 to Vwhich a -link 45 of the. governor is operatively at- I tached. A spring pressed-latch 46engages the end of arm 44 until such a time as the governor reaches the speed for which Vit is j the arm 44. When arm .44 released link 45'if'aises arm 44 s o as to close jaw members 41 and 42 upon the governor rope 35 and thus'stopitsmovement. Jaw 42 is pivotally mounted at 47 n a rod 48 which is slidably carried in a guide support 49 and provided with a spring 50 which urges the jaw 42 in to engagement with the governor rope 35, but allows rope 35 to slide th'rough the jaws when the tension yexceeds an amount determined by thepressure of spring 50. When thegovernor'l acts, due to overspeed of the carin the down direction, hitch 34 is withdrawn from releasing carrier 51 and as the elevator descends a tension is exerted on rope 32 to apply safety brake 24 to rails 16.

Referring to Figure 3'the safety plank 22,

. upon'which safety brakes 24 are mounted,

comprises two channels 55 and 56 secured in spaced relation by means of upper and lower plates 57 and 58 respectively. Abutments 59 are secured to the channels at their ends on opposite sides of the guide rail 16, and are" provided with lower yprojections 60 for guiding the actuating rods 67 and with upper projections 61'for taking the upward thrust of jaw members 52 and 53.

attached a and its Iabutment 59 are a pair of linksv 62,

.the ends o fwhich are rounded and lit in corresponding concave bearings formed in abutments 59 and jaw members 52 and 53,

aswill be best fseen in connection with jaw 52, when the side plates are removed. These links take the outward thrust of the jaws I and allow them toswing upwardly against fthe action of springs 463.

mounted between the supper surfaces ofjaws 52 and-53 and the projections 61 and in the released position of the safety brake act up- 'on the jaw members to hold their lower ends in engagement with projections 60. Adjust` ing sere-ws74 serve to regulate the pressure exerted by Springs 63.

In connection with jaw 53 (see alsok Figure 6) aK side plate 65'is shown secured on each side ofA abutment 59, by screws 75.v These side plates overlap the ends oflinks 62v and have pivotal, connections thereto vby pins 66. Slmilarly side plates 64l are securedto' jaw 53 and` have pivotal connections with links. 62 by pins 76. These side The" latter are plates hold the'parts in assembled relation L but are not called upon to transmit thrust between-jaw 53and' abutment 59.

Jaws 52 and 53 are oppositely cut away' on the twoy sides of guide rail 16,- so as vto form cam surfaces 77 which slope upwardly toward the guide rails with a considerable angle for a portion of their lengthand a small angle for the balance of their length. Stops 78 are provided at the upperends of the cam surfaces. Rollers 54 are rotatably mounted between the arms of forks 68 on pins 79. Forks-68 are pivotally carried on actuating rods 67.b pins 80, (see Figure 5). Act-uating ro s `67 pass upwardly through'the 'lower projections 60 on abutments 59 and carry the rollers in the space provided between cam surfaces 77- and rail 16.

from the surfaces of the guide rail 16 by means of iixed roller guides 69 secured to the lower projectionsA 60. Compression springs 70 ton rods 67, between a boss on roller guides 69 and heads 71 on the lower ends of the rods, tend to keepl the rods .and

In the' released position of the safety ybrake (Figure 3) the rollers are held .away

rollers -in the position shown in Figure 3. Cams 72 secured to shafts 23v are-provided to operate the actuating rods 67.

The operation of thesafetybrake' is as follows: Assuming that .j the elevator car is traveling downward at an excessive speed.

The governor trips, and jaws 41 and 42 grip the governor rope 35,' to bring it to a. stop.

, Hitch 34 is withdrawn from carrier 51 and, as the car proceeds downwardly, rope 32 against' springs 70. VAS rods 67 move upwardly, rollers 54 arebrought into contact with cam surfaces 7 7 and rail'l, the pivotal j connections between rollers 54 androds 67 permitting the rollers to'follow lthe cams.- Since thecaryisstill moving downwardly,v rollers '54 ride up cam surfaces 77 on jaws 52 and 53 until they reach the stops 78. As the rollers move upwardly, -jaws 52 and.53 move upwardly and outwardly on links 62, at the same time ,compressing springs l63.V lT Tlie parts are then in the positions .shown in' -Figure 4 and the safety brake is. applied. It will be noted that'stops 78 act in the manner 1.5V

Yzo

of brake shoes applied to rollers L54, Vwhich roll on the rail. The retarding force may 'A be varied by adjusting the pressure of springs 63 and will remain substantially constant for any adjustment, independent of the condition of the rail or surface of stops 78. lVere' the retarding force to become greater, springs 63 would compress, thereby permitting jaws 52 and 5310 move away from rail 16 by swinging 4on-links 62. iSuch movement would decrease the pressure acting to hold therollers against the Vrail and consequently the retardingforce.

In applying the safety, rope.32 rotates shaft 27 lthrough 90o andy when lever arml 30 acting through hitch 34 draws the governor has reached a horizontalposition, rope 32,

rope through jaws4l and 42 until the elevator is lbrought to a stop. v.`When it is i desired to. reset the mechanism :iaws4l and 42 are ymanually released-from rope 35 and latch 46 is :reset -Hitch'34vis replaced in the releasin carrier 5lI on -the elevatorf, Movement o? thegcar l in the up direction -will returnthe rollers 544 to their lower posi-` tion and thereby effect a release ,of the safety brakes;

' .i Buffers' 21, mountedv in' theielevator pit,

are, adaptedJto be'engaged by bumpers 81 on the bottom of the elevator and to bring the car to afstopj'in the event that the elevator car'continues to travel too far below itslowest landing level. Thereforeif the safety brake, be applied when the car reaches safety -bra'kes to 'stop the car.

the point where its bumpers 8l engage the buffers double retardation results due to the simultaneous action of both the buffers and As the retardation due to either the buffers lor safety brakes acting singly-is made the maximum commensurate with safety to passengers, the

' retardation due to'both the buffers and safety brakes acting together brings about a dangerous condition. In order to prevent the simultaneous action of the safety brakes and buffers, the thickness of the guide rail -16 is reduced .at 19 s o as to-effect a release f 4of the safety brakes at the time or shortly before bumpers 81 come into contact with the buffers 2l.

The reduced portion of the rail acts as ab v18 after they pass from the rail of normal tliirkness if the car goes on tothe bul'ers.

- In the foregoing disclosure the safety brakes havev been 'described as mounted on the .elevator Tear. However, safety brakes 'guide for the safety brakes and gui'd'e shoes may be similarly used on the counterweight.`

l. InY an elevator system' having a safety` i brake on a moving part adapted to cooperate with a stationary member throughout a portion of itspath to stop the'moving part and means foipreventing the retardation by the safety brake in another portionof its path. t i

. 2. In an elevator system provided with a safety brake and a buifer, means forpreventg simultaneous retardation by the safety brake and buffer.

3. In an elevator system, the combination of a safety brake on a moving part, a buffer mounted'in the path of the moving part for stopping it, and means for preventing the si for stopping the car and means fo-r preventl ing the simultaneous action of the two safety devices. v 6. In an elevator system the combination of a guide rail having a normal thickness for a portion of itslength andV a reduced thickness. for' another portion of its length, and an elevator car having ay safety brake adapted to grip the rail along the portion of normal thickness and incapable of gripping A A the rail along the portions of reduced thick-V ness. 3 7. In an elevator system the combination 'of a guiderail having a normal thickness for a portion of its length and a'reduced thickness for another portion of its length, an elevator car having a safety brake adapted to grip the rail along the portion of normal thickness and incapable of gripping the 1railalong the portions of reduced thickness,

and buffers adapted to engage the elevator .car at the part of its travel'where the safetybrakeis incapable of gripping the rail.v

8. Inan elevatorsystem including a guide rail for the elevator car, the combination of an elevator car having a safety 'brake thereon adapted to be actuated to grip the elevator` guide rail, governormeans operative to V s .the elevator car upon its passing act-nate said safety brake into gripping en- =.gagemen't with the rail when the elevator is 'traveling downwardly above a predetermined. speed, means for releasing' the grip li of said'rsafety brake on the rail at a point ladjacent to the bottom ofthe elevator hatchway, andv buffers adapted'to be engaged byv the elevator at said point-'and bring the elef vator to a stop independent of said safety 9. In'an elevatorlsysteinithe combination of a guide rail having, a certaln thickness f along the path ofthe' normal travel of the elevator car and a reduced thickness along Y l5 the path below thenormal travel of the car, l y agsafety brake on 4the car controlled by the speed ofthe car-to grip the rail in theevent of excessive speed of the car in the ldownward direction along the path of the normal travel of the car and incapable of gripping the-ra'rl along the portion of the rail having a reduced thickness, and a buifer disposed in the elevator pit adapted to be engaged by below .the limit (of. normal travel.

10,111- an elevator. systema,guide rail having one thickness for a portion -of its length, and a reducedthickness for another portion of its length.

11. In an elevator system, a guide rail having one thickness inthe elevator hatch- Way along the normal path of travel vof the elevator-car, and having a reduced thickness Afor a distancebelow the normal path of travel of the car. .Y

, 12. A safety brake for elevators comprising apair of 4jaws having cam" surfaces,- means for supporting said jaws on the elevator car on-opposite sides of the elevator guide rail, and a roller, disposed between `.each jaw and -the'rail and adapted to be brought in to engagement with vthe rail.

13. A safety brake for ,eleva-tors.. compris- 'ing elements for engaging the-sides Mof the 5 elevator guide rail, means for actuating said i elements into engagement with the' rail, a jaw on each side of the guide rail between which jaws and they rail said elements are disposed, supporting means for'said jaws comprising abutments and links arranged substantially normal lto the rails, said links being between the backs of the jaws and the abutments, and springs between said abutments andv said jaws adapted to exert a pressure upon the jaws substantially parallel 'with the rail, whereby a substantially constant retarding force of the safety brake is maintained.

14:. A safety brake for elevators comprising a pair of rollers, a jaw disposed on each side of the rail and having an inclined cam surface between' which cam surfaces and the rail said rollers are disposed, means for actuating said rollers along the cam surfaces into engagement with theA rail, and a stop '.on said jaws at onel end of said cam surfaces v for limiting the movement o f the rollers.

15. 'A safety, brake for elevators comprising a -pair of rollers, a jaw disposed ori-*eachside of the rail'and. having an inclined .ca-m surface between which cam surfaces'and the railsaid rollers are disposed, means `for -actu'atin'g said rollers along the cam 'surfacesf into engagement .'With the rail, and a stop on said jaws at/one end of. said cam surfaces for limiting the movementl of the rollers along the cam, and resisting their rotation `about their axes;

16. A safety brake for elevators compris- 1 ing a pair of rollers, a jaw.dis'posed-on'eachv 69 .side of the rail and having an inclined cam surface between which cam surfaces andthe *'rail' said rollers are dispose di,'means for actuating said rollers along the camsurfaces into engagement with the ralil, a sto j on-said limiting theniovement of the rollers along' the cam, and resisting their'rotation' about their axes, means for applying aA pressure vator guide rail, a jaw on each vside of thef rail having cam surfaces for guiding said rollers andholding` them in engagement* with the. rail,'rods connected with said rollers, 'and means for actuating said rods to move said rollers along the ycam surfacesinto their engaged positio i' ing'rollers for engaging the sides ofthe elevator guide rail, a jaw on eachside `of the "rall having cam surfaces for guiding said ico' 18. Asafetybrakefor elevatorscompris- 'rollers and holding y them in engagement ers, means lfor actuating said rods to move said-rollers along the cam surfaces into' their engaged position, and means for holding the lwith thekrail, .rods connected with said roll-V rollers out of engagement with Ithe rail when j the safety brake is released. d, l 19. safety brake. for'lele'vators comprising an abutment on each side of 'the elevator guide rail, a jaw disposed betweenl each of said abutments and the rail andprovided with a ycam surface inclined upwardly to.- ward the'rail, a pair of links extending between each abutment and a jawl and arranged substantially at right angles with respect to the rail, springs between the up-f per ends of vthe jaws and theabutments arranged. to 4exert a pressure on said jaws in a direction substantially parallel with the rail. rollers inthe space :between the cam surfaces on the jaws and the rail, rods connected with saidrollers and extending downwardly through saidv abutments, sprines on the rods between said abutments and the lower ends said rods operating on the Y ed 85 jaws atone end of saidl camsur aces for rods to' draw the rollers to the lower position an abutment on each side of the elevator between the jaws and the rail, and means guide rail, a aw disposed between each of 15 adapted to raise said rods so as to aetuate saidYa-nutments an the rail and provided the rollers'along said cam surfaces into enwith a' cam surface dined toward the rail,` l gagement with the rail. said jaws being-adapted to swing away V from 20. A safety brake'for elevators eompristhe rail while maintaining the 'cam surfaces' ing anabutment on eaoh side ofthe elevator in the same angular relation with respect 20 guide rail, a. jaw disposed between each of t0 the rail, and rail engaging members dissaid abutments and the rail and adapted to posed between said cam surfaces and the 10 swing away from the rail upon the retarding fallsy s force of the safety brake exceeding a pre- Ill testlmony Where/(2f, I have Slgned my determined amount, llame t0 this Spelflcatloll.

2l. A safety brake for elevators comprisf' DAVIDL. LINDQUIST. 

